A phototherapy device is an apparatus that includes one or more sources of light energy. A phototherapy device typically generates light energy for a particular desired purpose. For example, a phototherapy device may comprise a dermatologic device that generates light energy for application to skin, e.g., for hair removal, acne treatment, tattoo removal, etc.
The operation of a phototherapy device generally involves, among other things, the generation of heat by the device. Such heat generation typically involves the production of multiple heat loads within the phototherapy device. By way of example, the phototherapy device light source produces heat. Also, the phototherapy device electronics (e.g., power supply, control circuitry, etc.) typically generates heat.
In addition, during operation a phototherapy device may be subjected to external heat loads or heat sinks that involve the transfer of heat to the phototherapy device (i.e., external heat load) or from the phototherapy device (i.e., an external heat sink). By way of example, a phototherapy device comprising a dermatologic device may receive heat due to contact with skin. In such case, the temperature of the portion of the dermatologic device that contacts the skin is less than the temperature of the portion of the skin contacted. Such a device (i.e., a device in which the temperature of the skin-contacting portion is less than the temperature of the skin portion contacted) may prove effective to cool the skin and help protect users with darker skin types. By way of further example, a dermatologic device may maintain its skin-contacting portion at a temperature that is greater than the temperature of the portion of skin contacted. In such latter case, the skin may be considered an external heat sink, while in the former case the skin may be considered an external heat load. Also, by way of further example, a phototherapy device comprising a dermatologic device may dissipate heat into the air of the room in which this device is used. In such case, the ambient conditions comprise a heat sink.
A problem associated with phototherapy devices, then, involves the control and management of heat sinks and heat loads, both internal and external to the device, including without limitation the control and management of heat transfer between one or more of such heat sinks, heat loads, and the device, to promote efficient and enhanced device operation and performance.